272 cam + auto-tranny = High stall torque converter?

[Anonymous]

...what xecute said...
Also, chances are that the manifold vacuum is just a little low for the power valve that is presently in the carb: this is common when long duration cams are added to limited-intake engines, like these 200s.

My 2 cent's worth: make sure the float level is not too high, either from excessive fuel pressure or wear, and go down 1 or 2 steps on the power valve. Auto-trans cars need lower power valve numbers than manual cars, all else being equal. If that carb came from a manual-trans setup, it probably needs a little tweaking to make the power valve less likely to drop open until your foot is further into it.

 

[Anonymous]

cfmustang,

Have you fixed all the problems? How is the car running now? I'm reaaly interested on how this all works out. Keep us(ME) updated.

Thanks.

 

[cfmustang]

Sorry I didn't get back to you guys. I was off in Vegas getting married!

I haven't really any chance to work on the car since the initial post (moved, married, etc.) but I am hoping to start tinkering this weekend.

I can say that one weekend I got to take it out for an extended drive. Once the car really warmed up, the stalling problem seemed to nearly disappear. I could stop at a few lights and leave it in gear without it stalling, but it was right on the threshhold. I could also feel it surging to where the brakes were struggleing to hold the line.

Unfortunately, while crusing on the freeway, I found out my driver's side rear brake shoes were dragging and started smoking up a storm (going to fix that tonight, weather permitting).

To answer a few questions, the distributor is stock. I purchased a Ignitor II and Flamethrower II that I was going to install this weekend, but should I hold out till after I get the carb problems worked out?

As for the carb, I bought it new from Clifford (back in the day when they sold the 32/36) and besides some idle adjustments, I am assuming it should be setup/tuned to the factory Weber settings.

Like I said, I was running this carb with the same setup years ago without this issue. It was after I had the head work done (better breathing?) that this started.

My biggest problem is that I know nothing about carbs! I have the Weber manual but it is written with the assumption that the reader has a basic understanding of how the carbs work. Anyone know a good book for beginners?

 

[80broncoman]

More initial spark lead.

I think if it not pinging then the timing is not to high.
stock timing numbers for a 66 stang might be right on if you could find some fuel like we had in the 60's

 

[Anonymous]

CF - You need to replace your distributor for one with mechanical advance. This is going to help off the line and give you some more power alltogether. You should be able to use that Ignitor II you bought with a '68-'73 distributor. I woulnd't mess with anything on the carb until you get the timing (curve) squared away.

 

[Anonymous]

Sorry I didn't get back to you guys. I was off in Vegas getting married!

Congrats CF.

 

[cfmustang]

Thanks! It has been a busy few weeks...

Is that 68-73 (does it matter if it is for the 200 or 250?) distributor a direct swap or are there any modifications? i.e. different connections to the carb, coil, etc.

Any help would be appreciated...

 

[Anonymous]

Any '68-'73 distributor from a 170, 200, or 250 will work fine. They use the small female terminal cap so all your wiring is the same, will work fine with the Flamethrower coil, and just run the vacuum line to the ported vacuum nipple on the Weber.

 

[cfmustang]

After doing some quick research, it looks like the Ignitor II I bought will not work on the newer distributor. There are two models. One for use with the smog pump and one without. Mine does not have the smog pump so the shaft is solid with one side flattened.

Does anyone have the 68-72 dist. and can tell me what the rotor shaft looks like? Is it solid with a flat side or is it hollow with a notch in one side (kind of like the letter "C")?

Also, is the 12127C distributor on this page : http://store.cal-mustang.com/cm_able/showdetl.cfm?&DID=7&Product_ID=3617&CATID=19 the correct distributor?

 

[Anonymous]

CF,

Why not a duraspark distributor?

 

[cfmustang]

Seemed more complex than I wanted to get into in the first place. The pertronix is so simple. Besides, I perfered the look of the original.

Also, now I have the money sunk into the Ignitor II. If I have to, I can probably exchange the one version for the other.

 

[Anonymous]

CF - I bought a Pertronix for a '68 distributor and realized I had a '66 distributor. I installed it anyhow and it worked fine. That was 5 years ago though...

 

[cfmustang]

It looks like the difference is if it will fit on the rotor shaft. I'll just have to try it and see if it fits.

In your case, it appears that all 68s use the smog pump shaft and some 66s use the smog pump shaft. It is possible that they were the same for you. However, my 66 is non-smog so it looks like they will be different.

Won't know till I see one though.

 

[cfmustang]

Inliner,

Just to clarify the terminology before I buy. You mentioned a mechanical & vacuum advance. When I have been pricing the distributor, I have only seen single and dual vacuum advance.

Is the dual vacuum advance the same as the mechanical & vacuum you mentioned?

I found it at Autozone for $38 bucks, but they have to order it so I wanted to get it on order after work today... That way I would get it in two business days and it gives me a chance to try and tune the carb a bit this weekend first.

Thanks for all your help

-Chris

 

[Anonymous]

CF - Order the distributor with "single advance". They are talking about the vacuum advance portion. Both have a mechanical advance system, but the dual advance has 2 ports on the vacuum canister for a manifold vacuum source (which actually retards timing during idle and decceleration).

Just tell them you have a '70 Mav with a 200 and need a "single advance" type. That should narrow it down to what you need.

 

[cfmustang]

Just a quick update.

Didn't get to start my engine tuning because the brakes became a much bigger issue (both front cylnders leaking, rear wheel bearing bad - leaking grease was causing the smoke, and a total brake job required. Oy!)

However, when I took it out for another spin on Saturday morning, it was running much better! Now, it is still running way too rich because when the car was idleing in the garage (with the door open, obviously) my wife could smell the gas inside the house. Once, it warmed up (10 minutes) I was able to put it in gear with the brakes engaged and no stalling.

Now, the idle is still really rough and it seems to be more than just cam lope. I mean the engine is just plain shaking. Also, my high speed idle is way too high (unfortunately, my tach is not working since the rebuild so I have to get my hands on one to get some numbers) but the low speed idle isn't too far off.

I think my new plan of attack is this. Weber has instructions on resetting the carb published everywhere, so I am first going to take the carb back to square one and get that tuned the best I can. From there, I will tackle any distributor issues, but it seems to me that this would be affecting acceleration and not idle, isn't that correct?

Could the original stalling in gear issues be related to break in? If I am on the wrong track, please let me know...

 

[Anonymous]

CF,

What's your rear gear ratio?

Dennis

 

[cfmustang]

The stock 7 1/4" rear with 4 lug drums, so that should be the 2.73 gears.

 

[Anonymous]

CF,

Jack always says that most "too rich" conditions may be caused by bad timing or other ignition problem. Maybe changing out the load-a-matic dizzy for a newer one like Inliner suggested is the best move. Anyhow I'm totally interested in this cause I may go this same route with the biggish 272 cam and C4.

DB

 

[wsa111]

if you put the pertronix II in the distributor, take it out & install a pertronix I, or put in the durospark distributor. you can look at my previous posts on this pertronix problem. i don't know if i got a defective one, but from the number of posts on rough idle i beleive pertronix has a problem with the #II unit. also get a full 12 volts to the coil by bypassing the resistor. hope this helps with your problem. if it does not help you have furthur problems with your carburetion & or your initial advance setup. the wilder you go with the cam it requires more initial advance but remember not to go over 36-38 degrees total. thats the initial plus the centrifigul advance. if what i stated is beyond your expertice, get some professional help.
if this turns out to be a weber problem get some advise from xtaxi or addo. these fellows know this system. i can help with the 1100 or the 2300 holley carbs. hope this helps. william